Method for forming an information recording medium having information on spare area, and method and apparatus for recording/reproducing data to/from the medium

Abstract

This invention provides an information recording medium, and a method and apparatus for writing to/reading from a recording medium in which a starting point of a spare area is variable relative to a starting point of a data area. Information concerning a variable boundary between the data area and the spare area is stored on the recording medium. A method and apparatus for writing/reproducing data to/from the recording medium is also provided. In a preferred embodiment, the recording medium is an optical disc.

What is claimed is:  
     
       1. A method for writing information to an information recording medium having a plurality of zones, each zone having a data area for recording data and a spare area for replacing defective units within the data area, wherein a ratio between a spare area size and a data area size in at least one zone is different as compared to a ratio between a spare area size and a data area size in another zone, the method comprising the steps of: 
       writing information to a predetermined area on the information recording medium, wherein the predetermined area is separate from the spare areas and the data areas, the information identifying a ratio between a data area and a spare area for at least one zone; and  
       controlling recording of information in the data areas and spare areas of the information recording medium based, at least in part, upon the information stored in the predetermined area.  
     
     
       2. The method according to  claim 1 , wherein the predetermined area is at least one of a lead-in area and a lead-out area on the information recording medium. 
     
     
       3. The method according to  claim 1 , wherein the information recording medium is an optical disc. 
     
     
       4. The method according to  claim 1 , wherein the information stored in the predetermined area is sufficient to show a size of the spare area and a size of the data area. 
     
     
       5. An apparatus for writing information to an information recording medium having a plurality of zones, each zone having a data area for recording data and a spare area for replacing defective units within the data area, wherein a ratio between a spare area size and a data area size in at least one zone is different as compared to a ratio between a spare area size and a data area size in another zone, said apparatus comprising: 
       writing circuitry to write information to a predetermined area on the information recording medium, wherein the predetermined area is separate from the spare areas and the data areas, the information identifying a ratio between a data area and a spare area for at least one zone; and  
       a controller controlling the recording of information in the data areas and spare areas of the information recording medium based, at least in part, upon the information stored in the predetermined area.  
     
     
       6. The apparatus according to  claim 5 , wherein the predetermined area is at least one of a lead-in area and a lead-out area on the information recording medium. 
     
     
       7. The apparatus according to  claim 5 , wherein the information recording medium is an optical disc. 
     
     
       8. The apparatus according to  claim 5 , wherein the information stored in the predetermined area is sufficient to show a size of the spare area and a size of the data area. 
     
     
       9. An information recording medium, comprising: 
       a plurality of zones, each zone having a data area for recording data and a spare area for replacing defective units within the data area, wherein a ratio between a spare area size and a data area size in at least one zone is different as compared to a ratio between a spare area size and a data area size in another zone; and  
       a predetermined area separate from the spare areas and the data areas, the predetermined area including information identifying a ratio between a data area and a spare area for at least one zone.  
     
     
       10. The information recording medium according to  claim 9 , wherein the predetermined area is at least one of a lead-in area and a lead-out area on the information recording medium. 
     
     
       11. The information recording medium according to  claim 9 , wherein the information recording medium is an optical disc. 
     
     
       12. The information recording medium according to  claim 9 , wherein the information stored in the predetermined area is sufficient to show a size of the spare area and a size of the data area.